Thermal-mechanical Coupling Analysis And Optimization Design Of Compressor Vane Carrier Model

Compressor vane carrier is the shell of compressor part mainly under gas pressure and temperature load in gas turbine. Thermal equilibrium, ovality and structural lightweight are the main problems that engineers are focused on in design of compressor vane carrier. But structural analysis of compressor vane carrier takes too much time and leads to more difficulties in optimization design because complex structure of compressor vane carrier must be taken into account under conditions of variation of temperature and pressure load during the whole time from starting to stable running until closing. In the present paper, thermal-mechanical coupling analysis of compressor vane carrier is completed. Geometric size and bolt pretension of compressor vane carrier is optimized based on algorithm of efficient global optimization (EGO) after simplifications of geometric model and boundary loading are completed. The following four parts are included in as the main work of this paper:(1) Theory of Kriging model and the usage method of MATLAB DACE toolkit are introduced. Details on theory and advantage of EGO algorithm are highlighted. Diagram of structural optimization design based on EGO algorithm is given. Accuracies of EGO algorithm and which of traditional Kriging algorithm are compared by taking Branin function as an example.(2) Thermal-mechanical coupling analysis is completed on the 3D finite element model of compressor vane carrier. Distributions of temperature and radial displacement of compressor vane carrier at different time stage are studied. The maximum stress and ovalizaion in sensitive region are focused on.(3) Simplifications of geometric model and boundary loading of compressor vane carrier are completed. Geometric model is simplified in meshing procedure based on the similar temperature distribution and radial displacement of original model. It is found that computing time of simplified geometric model reduces to less than half of which of original model. Then, a method to simplify the boundary loading is proposed and applied to the structure of compressor vane carrier for the problem of engineering numerical analysis under multiple types of loading and multiple time steps. It is shown that computing time of simplified geometric model with simplified loads reduces further to less than quarter of which of original model.(4) Multi-objective optimization of compressor vane carrier is presented based on EGO algorithm. Bolt pretension, bolt flange height, heat balance flange height and width are taken as the design variables. Maximum stress and ovalizaion of compressor vane carrier are chosen as the objective function. Pareto front curve is obtained and the typical optimization solutions are analyzed and compared.